My Great Granduncle
They would be your grandparents brother of sister
granduncle - grandnephews/grandnieces
the second hokage was Tsunade's granduncle
keke palmer is my cousin her grandpa is my granduncle
You would be their great-granduncle or great grand aunt, and they are your great-great nieces or great-great nephews.
You are the nephew if you are male and a niece if you are female.
Your grandmother's brother is your children's great-granduncle (or great great uncle). They are his great-grandnieces and great-grandnephews.
Bullroarer was huge for a hobbit--he could ride a horse. Bullroarer was the great-granduncle of Old Took, which was Bilbo's grandfather.
just the first and second are brothers but the rest are not
Your great grand unlce's great grandniece could be you (if you are a girl), any of your sisters, or some of your first cousins or second cousins or third cousins who are girls.
my nephew had a baby...his mother is my sister...she is now a grandma which "should" make me a granduncle...and our mother is now a great grandma which "should" make her brother a great grand uncle.